ORIGIN AND EVOLUTION OF RETROELEMENTS BASED UPON THEIR REVERSE-TRANSCRIPTASE SEQUENCES
ORIGIN AND EVOLUTION OF RETROELEMENTS BASED UPON THEIR REVERSE-TRANSCRIPTASE SEQUENCES
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DOI：
10.1002/j.1460-2075.1990.tb07536.x
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发表时间：
1990-10-01
期刊：
影响因子：
11.4
通讯作者：
EICKBUSH, TH
中科院分区：
文献类型：
--
作者：
XIONG, Y;EICKBUSH, TH
为研究逆转录酶基因的进化关系，构建了动物、植物、原生动物和细菌共82个逆转录酶基因的系统发育树。该树基于在所有RT中鉴定的总共178个残基的7个氨基酸结构域。我们还确定了这七个结构域的RNA定向RNA聚合酶从各种正链RNA病毒。这些RNA聚合酶与RT的序列相似性表明这两种酶从共同的祖先进化而来，因此RNA聚合酶可以用作RT树的外群。比较的遗传组织的各种RT包含的元素和它们的位置上的树允许几个推论有关的起源和进化这些元素。目前的逆转录因子最可能的祖先是一个逆转录转座因子，既有gag样基因，又有pol样基因。在该树的一个主要分支上，细胞器和细菌序列（例如II组内含子和细菌msDNA）似乎已经捕获了来自缺乏长末端重复（LTR）的反转录转座子的RT序列。在另一个主要的分支上，LTR的获得产生了两组不同的LTR逆转录转座子和三组病毒：逆转录病毒、嗜肝DNA病毒和花椰菜花叶病毒。
To study the evolutionary relationship of reverse transcriptase (RT) containing genetic elements, a phylogenetic tree of 82 retroelements from animals, plants, protozoans and bacteria was constructed. The tree was based on seven amino acid domains totalling 178 residues identified in all RTs. We have also identified these seven domains in the RNA-directed RNA polymerases from various plus-strand RNA viruses. The sequence similarity of these RNA polymerases to RT suggests that these two enzymes evolved from a common ancestor, and thus RNA polymerase can be used as an outgroup to root the RT tree. A comparison of the genetic organization of the various RT containing elements and their position on the tree allows several inferences concerning the origin and evolution of these elements. The most probable ancestor of current retroelements was a retrotransposable element with both gag-like and pol-like genes. On one major branch of the tree, organelle and bacterial sequences (e.g. group II introns and bacterial msDNA) appear to have captured the RT sequences from retrotransposons which lack long terminal repeats (LTRs). On the other major branch, acquisition of LTRs gave rise to two distinct groups of LTR retrotransposons and three groups of viruses: retroviruses, hepadnaviruses and caulimoviruses.